Lexus SC300 / Lexus SC400. Manual - part 444

(e)  Remove the following parts:

(1)

Wave washer

(2)

Camshaft sub–gear

(3)

Camshaft gear spring

HINT: Arrange the camshaft sub–gears and gear springs (RH
side and LH side).

43.  REMOVE CIRCULAR PLUGS

Remove the two bolts, seal washers, bearing cap and circular
plug. Remove the two circular plugs.

HINT: Arrange the bearing caps (RH side and LH side).

44.  DISCONNECT MAIN OXYGEN SENSOR CONNECTORS

Disconnect the RH and LH oxygen sensor connector.

EM–74

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ENGINE MECHANICAL

Cylinder Heads

45.  REMOVE CYLINDER HEADS

(a)  Uniformly loosen the ten cylinder head bolts on one side

of each cylinder head in several passes in the sequence
shown, then do the other side as shown. Remove the
twenty cylinder head bolts and plate washers.

NOTICE: Head warpage or cracking could result from re-
moving bolts in an incorrect order.

(b)  Lift the cylinder heads from the dowels on the cylinder

block, and place the two cylinder heads on wooden
blocks on a bench.

HINT: If the cylinder head is difficult to lift off, pry between the
cylinder head and cylinder block with a screwdriver.
NOTICE: Be careful not to damage the contact surfaces
of the cylinder head and cylinder block.

46.  REMOVE EXHAUST MANIFOLD FROM RH CYLINDER

HEAD
(a)  Remove the three bolts and heat insulator.

(b)  Remove the main oxygen sensor.

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ENGINE MECHANICAL

Cylinder Heads

EM–75

(c)  Remove the eight nuts, exhaust manifold and gasket.

47.  REMOVE EXHAUST MANIFOLD FROM LH CYLINDER

HEAD
(a)  Remove the three bolts and heat insulator.

(b)  Remove the main oxygen sensor.

(c)  Remove the eight nuts, exhaust manifold and gasket.

DISASSEMBLY OF CYLINDER HEADS

(See Components on page 

EM–59

)

1. 

REMOVE VALVE LIFTERS AND ADJUSTING SHIMS

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ENGINE MECHANICAL

Cylinder Heads

HINT: Arrange the valve lifters and adjusting shims in correct
order.

2. REMOVE 

VALVES

(a)  Using SST, compress the valve spring and remove the

two keepers.

SST 09202–70010

(b)  Remove the following parts:

(1)

Spring retainer

(2)

Valve spring

(3)

Valve

(4)

Spring seat

HINT: Arrange the valves, valve springs, spring seats and
spring retainers in correct order.

(c)  Using needle–nose pliers, remove the oil seal.

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ENGINE MECHANICAL

Cylinder Heads

EM–77